Constitutional tolerance to heavy metals of a fiber crop, ramie (Boehmeria nivea), and its potential usage

It is observed that ramie (Boehmeria nivea), an economic fiber crop, can establish and colonize metal-contaminated sites in China. Metal tolerance and accumulation by ramie originating from 13 metal-contaminated and 4 "clean" sites in China were compared under field and hydroponic conditions. All selected populations and germplasms displayed good growth performance under diverse metal-contaminated habitats; while growth responses, metal accumulation and tolerance were similar among the 8 populations and 2 germplasms when exposed to solutions containing elevated As, Cd, Pb, or Zn in the laboratory. These revealed that ramie possesses a certain degree of constitutional metal tolerance. To our knowledge, this is the first report of constitutional metal tolerance possessed by a fiber crop. Ramie can be considered as a good candidate for both fiber production and phytoremediation of sites contaminated by multi-metals, as it accumulates relative low metal concentrations, but possesses both high biomass and high economic value.

Effects of spironolactone on atrial structural remodelling in a canine model of atrial fibrillation produced by prolonged atrial pacing

BACKGROUND AND PURPOSE

Suppression of the renin-angiotensin-aldosterone system can prevent atrial fibrillation (AF) by attenuating atrial structural remodelling but the role of aldosterone in AF prevention has not been investigated thoroughly. We explored whether the aldosterone antagonist, spironolactone, could improve atrial structural remodelling in long-term rapid pacing-induced AF.

EXPERIMENTAL APPROACH

Three groups of dogs were used, sham-operated, control and spironolactone-treated groups. Dogs in the control and spironolactone groups had right atrial pacing for 6 weeks. The spironolactone group was given spironolactone 1 week before and during the atrial pacing. After 6 weeks of pacing, atrial structural and functional changes were assessed by echocardiography, haemodynamic parameters by cardiac catheterization, histopathological changes by light and electron microscopy and cardiomyocyte apoptosis by TUNEL. Caspase-3, Bcl-2, bax, calpain I, calpastatin, matrix metalloproteinase (MMP)-9 and tissue inhibitors of metalloproteinase (TIMP)-1 were analysed by immunohistochemistry and Western blotting. The inducibility and duration of AF were measured by atrial burst pacing.

KEY RESULTS

After atrial pacing, the proportion of TUNEL positive cells, myolysis, atrial fibrosis and dilatation were all significantly increased and these changes were inhibited by spironolactone. Spironolactone treatment reversed the increased expression of caspase-3, bax, calpain I and MMP-9 and the decreased level of Bcl-2, calpastatin and TIMP-1, induced by chronic atrial pacing. Also spironolactone prevented the increased inducibility and duration of AF, induced by tachypacing.

CONCLUSIONS AND IMPLICATIONS

Treatment with spironolactone prevented myocardial apoptosis, myolysis, atrial fibrosis and dilatation, suggesting a possible beneficial effect of aldosterone antagonism on atrial structural remodelling in AF.

Morphological analysis of the lung of neonatal yak

Although yaks play an important role as companion or pack and draught animals on Chinese plateaus in alpine and sub-alpine regions, morphological studies and anatomical data on the lung of yak are sparse. To provide anatomical descriptions and morphometric data, 10 one-day-old yaks were examined by means of dissection, light and electron microscopy. The measurements of lung were made on dissected specimens and histological sections. Unequal dichotomous branching was demonstrated in the dissected tracheobronchial tree. The diameters of bronchial airways and height of epithelium were measured, and showed that the variation of diameters in airways was always greater than that of height of epithelium. In addition, the thickness of muscularis, cartilage and adventitia was examined, as well as the number of goblet and Clara cells in airways. Ultrastructural studies showed that the surface epithelium was mainly composed of goblet, ciliated, Clara and basal cells, similar to that in other domestic animals. Under electron microscope, two distinctive types of ciliated cells could be seen in the tracheobronchial epithelium. The first type contained some mitochondria, distended smooth endoplasmic reticulum (SER), little rough endoplasmic reticulum (RER) and numerous vacuoles in electron-lucent cytoplasm. The second type had dense cytoplasm with abundant mitochondria, RER and no vacuoles. Both types were rich of glycogen granules. The goblet cells in neonatal yak lung had the following characteristic features: dentate nucleus in dense cytoplasm, with stacks of RER and numerous dense membrane-bounded mucous droplets, which were round or oval, often with an electron-lucent core. The droplets were not confluent. Glycogen granules were numerous, and Golgi complex was occasionally present. Clara cells were dome-shaped and usually protruded into the airway lumen. Large amounts of SER and many secretory droplets were found within the cytoplasm. Several typical 'clefts' were also found in the cytoplasm.

MR imaging of adenomas of the nonpigmented ciliary epithelium of the eye

BACKGROUND AND PURPOSE

ANPCEs are rare benign tumors of the eye arising from the NPCE in adults, which may be clinically mistaken for melanoma. This study was undertaken to delineate clinical and MR imaging features of these tumors.

MATERIALS AND METHODS

Clinical presentation and MR imaging findings of 8 patients (6 women and 2 men; median age, 51 years) with pathologically confirmed ANPCEs were retrospectively reviewed. Location, size, shape, margin, signal intensity, and gadolinium-enhancement characteristics of all tumors were evaluated. Signal intensity and degree of enhancement were graded in comparison with the ipsilateral lacrimal gland.

RESULTS

MR imaging revealed a circumscribed enhancing mass within the ciliary body of the eye in all 8 patients. The mass was ovoid in 6 patients and spheric in 2. Gadolinium enhancement was marked in 4 lesions and moderate in the other 4. Both T1 and T2 relaxation times were qualitatively identical to those in the lacrimal gland in 2 tumors. In the remaining 6 tumors, the T1 was identical to and the T2 longer than that in the lacrimal gland.

CONCLUSIONS

ANPCE should be included in the differential diagnosis of a spheric or ovoid enhancing ciliary body mass with T1 similar to that in the lacrimal gland and T2 equal to or longer than that in the lacrimal gland.

CT Based Lymphatic Mapping and Localization – A New Method To Detect Sentinel Lymph Node in Breast Cancer Patients

Background: Sentinel lymph node biopsy in breast cancer patients has not been extensively accepted in mainland China. The main reason is that radioisotope tracer is not available in many hospitals. The objective of this study is to explore CT based lymphatic mapping and localization. The accuracy will be evaluated comparing SLN found by CT with those found by isotope and blue dye.Methods: 18 breast cancer patients who diagnosed by core needle biopsy or excisional biopsy underwent CT scan to locate the SLN before SLNB at the same day of surgery. When CT examination performed, those patients were in supine position, with the arms stretched upward but bent at the elbow with the hands at the side of the cranium which similar to the surgical position. After local anesthesia, 2mL of iopamidol was injected subcutaneously to the peritumoral and peri-areolar areas followed by gentle massage for about 1 minute. Contiguous 2-mm-thick CT images that included the breast and axilla were obtained prior to administration of the contrast agent. After 3D CT reconstruction, the SLN was identified as the most inferiorly visible nodule in the axilla connected to the lymphatic vessel on the CT imaging monitor. A professional intervention doctor punctured the defined lymph node guided by the CT monitor using the Breast Lesion Localization Needles (interv). The needle would stay in the patient's axilla until the surgery. All the lymph nodes including the CT defined one and which marked by methylene blue dye or 99mTc-sulfur colloid tracers were removed, which then would be tested by touch imprint cytology for the intraoperative diagnosis. Patients who had positive SLN would receive axillary dissection. We evaluated the new method by comparing lymph nodes defined by CT and traditional ways.Results: In this study, the success rate of SLNB was 100% (18/18). 15 of 18 patients (83.3%) showed the direct connection of SLN and lymphatic vessels draining from the injection sites on CT monitor successfully. 13 of 15 patients' SLN localization corresponded well with SLN identified by the traditional SLN mapping. Of the 40 SLNs in 15 patients, 7 SLNs in 3 patients were positive and received the ALND. These 7 SLNs were all clearly visualized on CT monitor. Among 15 SLNs (in 15 patients) punctured by needles, 13 SLNs had the highest radioactivity by DGP-guided probe and 12 are blue dye–stained. All of the 15 SLNs had radioactivity or blue stained. None of these 18 patients showed any adverse events during or after CT examination and surgery. With the assistant of CT location, the mean time of SLNB had been shortened from 20 mins to 16 mins.Conclusion: Comparing with usual tracing method, CT guided axillary SLN mapping and localization showed good specificity and gave concordant results in locating sentinel lymph nodes. These results suggest that CT guided localization would be a valuable tool for identify sentinel lymph nodes in breast cancer patients.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1035.

Activity-mediated plasticity of GABA equilibrium potential in rat hippocampal CA1 neurons

The equilibrium potential (E(GABA)(-PSC)) for gamma-aminobutyric acid (GABA) A receptor mediated inhibitory postsynaptic currents (PSCs) in hippocampal CA1 pyramidal neurons shifts when theta-burst stimulation (four pulses at 100 Hz in each burst in a train consisting of five bursts with an inter-burst interval of 200 ms, the train repeated thrice at 30-s intervals) is applied to the input. E(GABA)(-PSC) is regulated by K(+)/Cl(-) co-transporter (KCC2). GABA(B) receptors are implicated in modulating KCC2 levels. In the current study, the involvement of KCC2, as well as GABA(B) receptors, in theta-burst-mediated shifts in E(GABA)(-PSC) was examined. Whole-cell patch recordings were made from hippocampal CA1 pyramidal neurons (from 9 to 12 days old rats), in a slice preparation. Glutamatergic excitatory postsynaptic currents were blocked with dl-2-amino-5-phosphonovaleric acid (50 microM) and 6,7-dinitroquinoxaline-2,3-dione (20 microM). The PSC and the E(GABA)(-PSC) were stable when stimulated at 0.05 Hz. However, both changed following a 30-min stimulation at 0.5 or 1 Hz. Furosemide (500 microM) and KCC2 anti-sense in the recording pipette but not bumetanide (20 or 100 microM) or KCC2 sense, blocked the changes, suggesting KCC2 involvement. Theta-burst stimulation induced a negative shift in E(GABA)(-PSC), which was prevented by KCC2 anti-sense; however, KCC2 sense had no effect. CGP55845 (2 microM), a GABA(B) antagonist, applied in the superfusing medium, or GDP-beta-S in the recording pipette, blocked the shift in E(GABA)(-PSC). These results indicate that activity-mediated plasticity in E(GABA)(-PSC) occurs in hippocampal CA1 pyramidal neurons and theta-burst-induced negative shift in E(GABA)(-PSC) requires KCC2, GABA(B) receptors and G-protein activation.

Functional gene silencing mediated by chitosan/siRNA nanocomplexes

Chitosan/siRNA nanoparticles to knock down FHL2 gene expression were reported in this work. The physicochemical properties such as particle size, surface charge, morphology and complex stability of chitosan nanoparticle-incorporated siRNA were evaluated. Nanoparticles which were formulated with chitosan/siRNA exhibited irregular, lamellar and dendritic structures with a hydrodynamic radius size of about 148 nm and net positive charges with zeta-potential value of 58.5 mV. The knockdown effect of the chitosan/siRNA nanoparticles on gene expression in FHL2 over-expressed human colorectal cancer Lovo cells was investigated. The result showed that FHL2 siRNA formulated within chitosan nanoparticles could knock down about 69.6% FHL2 gene expression, which is very similar to the 68.8% reduced gene expression when siRNA was transfected with liposome Lipofectamine. Western analysis further showed significant FHL-2 protein expression reduced by the chitosan/siRNA nanoparticles. The results also showed that blocking FHL2 expression by siRNA could also inhibit the growth and proliferation of human colorectal cancer Lovo cells. The current results demonstrated that chitosan-based siRNA nanoparticles were a very efficient delivery system for siRNA in vivo as previously reported.

Mechanical Properties of Nanomaterials Examined with a NI-AFM

The mechanical properties and strain rate sensitivity of nanocrystalline nickel was studied as a function of grain size at different temperatures in tensile tests and with a nanoindenter in order to examine the different deformation mechanisms of nanocrystalline materials. The effect of lateral boundaries and hydrogen on the nucleation of dislocations was studied in detail. For the first time it was possible to observe the reduction of the dislocation nucleation stress on a nanoscale. In addition the experiments yielded, depending on temperature and strain rate, the strain rate sensitivity, the activation volume and the creep exponents as a function of stress and grain size. From the creep experiments the transition between grain boundary sliding and dislocation climb as a function of temperature was obtained. The strain rate jump tests gave extremely small activation volumes, nearly a factor of 100 smaller than in conventional nickel as a function of grain size. To help in understanding this behaviour the strain rate sensitivity of single grains was tested with a nanoindenter. The results clearly showed that the primary interaction of dislocations with grain boundaries is the reason for the observed strong rate effects and small activation volumes.

Genomic full length sequence of HLA-Cw*030301, identified by cloning and sequencing

Genomic full length sequence of human leukocyte antigen (HLA)-Cw*030301 that differs from Cw*030401 by two-nucleotide exchange at nt 473 (G>A) in exon 2 and nt 3033 (G>C) in 3'UTR, was identified by cloning and sequencing from a male Chinese donor.

Surface Conditioning Influences Zirconia Ceramic Bonding

Air-abrasion seems to be mandatory for durable resin bonding to zirconia ceramic. Air-abrasion might compromise the ceramic strength by creating surface defects. Therefore, omitting air-abrasion or using reduced air-pressure seems desirable. We tested the null hypotheses that omitting air-abrasion or using reduced air-pressure does not affect zirconia ceramic bonding independent of using primers. Three mechanical surface conditions (polished, air-abraded at 0.05 or at 0.25 MPa) and 4 priming conditions were tested. After different surface conditioning, zirconia ceramic specimens were bonded, and tensile bond strengths were evaluated after water storage for 3 days or for 150 days with additional 37,500 thermal cyclings for artificial aging. Omitting air-abrasion resulted in debonding during artificial aging independent of using primers. The combination of air-abrasion and priming improved long-term resin bonding to zirconia ceramic significantly. With low-pressure air-abrasion, surface roughness was reduced without affecting long-term bond strength, provided that adequate adhesive primers were applied.

Rebound bursts in GABAergic neurons of the thalamic reticular nucleus in postnatal mice

Whole cell patch-clamp recordings from GABAergic cells of thalamic reticular nucleus (RTN) in thalamocortical slices made from postnatal day 6 (P6) to 10 (P10) were used to investigate the pattern of rebound bursts (RBs) triggered by an injection of hyperpolarizing current into RTN cells. The number of RBs in the RTN and the overlying Na(+)/K(+) spikes changed in an age-dependent manner. The generation of RBs depended largely on the amplitude of the after-hyperpolarizations (AHPs). RB patterns in response to hyperpolarizing current injection into relay cells were markedly different from RB patterns in RTN cells with an after-depolarization. GABA(A) receptor antagonist bicuculline methiodide (BMI) changed burst firing patterns, increasing the duration of RB and decreasing the amplitude of AHP in RTN cells. Furthermore, local puffs of NMDA in the presence of BMI induced RBs. K(+) channel blocker 4-aminopyridine partially mimicked the effect of BMI on AHPs. The shapes of RBs were altered by a selective CaMKII inhibitor KN-62, but not by an inactive analog KN-04.

Mesothelin as a marker of response in malignant pleural mesothelioma

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Background: Malignant pleural mesothelioma (MPM) is a rare malignancy related to asbestos exposure. Radiological assessment of disease status and treatment response using RECIST criteria is often difficult, therefore blood markers of disease burden may be useful adjunctively. Soluble mesothelin related peptide (sMRP) can distinguish between MPM and benign pleural disease. We performed an exploratory analysis to determine whether sMRP correlates with MPM disease course. Methods: From December 2006 to August 2008 blood samples were collected from MPM patients during clinic visits. Plasma sMRP levels were measured using the MESOMARK assay (Fujirebio diagnostics). Changes in sMRP levels were compared with corresponding radiological tests, scored as progression, stable or disease shrinkage. Results: From 41 patients, 165 samples were collected (median 4/patient; range 2–10). At study entry 34/37 (92%) patients with measurable disease had elevated sMRP (>9ng/ml, range 14–60). In 22 patients receiving chemotherapy or biologic therapy, relative (Fisher's exact test, p=3.2x10–6) and absolute (p=2.6x10–5) changes in sMRP correlated with radiological assessment (Table). All 4 post-surgery surveillance patients, with no evidence of recurrence, had normal sMRP levels (1.8–4.9). Of 8 patients who underwent surgical resection, 7 had elevated pre-operative sMRP that fell to normal post-operatively (Wilcoxon rank (WR) p=0.02). Absolute sMRP rose in all patients with radiological progression (systemic therapy, n=9, WR p=0.004; supportive care, n=10, WR p=0.02). Conclusions: sMRP levels not only correlate with surgical debulking but we report, for the first time, that they also correlate with treatment response and radiological progression in MPM patients undergoing systemic therapy or supportive care. sMRP may be a clinically useful biomarker in MPM clinical trials and in patient management. These findings should be validated prospectively.

[Table: see text]

[Table: see text]

Pegfilgrastim in pediatric sarcoma patients undergoing dose-intensive chemotherapy: Phase II study results

10024

Background: Children with cancer undergoing dose-intensive chemotherapy often require G-CSF support. Patients (pts) < 2 yrs have the highest risk of prolonged neutropenia due to imprecise dosing and immature drug clearance. Once-per-cycle pegfilgrastim may be beneficial due to neutrophil-mediated clearance that allows adequate serum levels throughout the neutropenic period. Young pts, who receive relatively more myeloablative chemotherapy, should have the highest pegfilgrastim exposure. Methods: Pts ≤21 yrs (age groups 0–5, 6–11, and ≥12 yrs) with sarcoma and scheduled to receive VAdriaC (cycles 1 & 3) and IE (cycles 2 & 4) were randomized 6:1 to receive pegfilgrastim 100 μg/kg or filgrastim (5 μg/kg/d until ANC ≥ 10×109/L) 24 hrs after chemotherapy administration. Post-nadir ANC recovery, incidence of ANC recovery by day 21 of cycles 1 & 3, pharmacokinetics (PK), and safety by age group were evaluated. Results: 43 pts (63% male) received pegfilgrastim (n=37) or filgrastim (n=6). Maximum pegfilgrastim concentration was achieved ∼24-hrs postdose and sustained until ANC nadir. Pegfilgrastim levels fell rapidly as ANC recovered. One child did not achieve ANC recovery by day 21 in cycle 1: an 8-mo-old 7.9-kg boy with non-metastatic undifferentiated sarcoma had 24 days of severe neutropenia in cycle 1. The youngest age group (including this child) had longer duration of severe neutropenia and, consequently, higher pegfilgrastim exposure ( Table ). Treatment-related adverse events were generally mild to moderate (pegfilgrastim 22%, filgrastim 33%); the only treatment-related event reported by >1 pt was bone pain (pegfilgrastim=11%, filgrastim=17%). Conclusions: ANC, PK, and safety profiles in pediatric patients were comparable with those in adults and support pegfilgrastim dosing across pediatric age groups. Consistent with neutrophil-mediated clearance, adequate exposure to pegfilgrastim was maintained in the youngest pts who received the most myelosuppressive chemotherapy.

[Table: see text]

[Table: see text]

MR imaging findings of the uveal schwannoma

BACKGROUND AND PURPOSE

Uveal schwannoma is a rare benign neoplastic proliferation of pure Schwann cells. The purpose of this study was to describe MR imaging features of uveal schwannoma.

MATERIALS AND METHODS

MR images in 6 female patients with uveal schwannoma confirmed by pathologic examination were retrospectively reviewed. MR imaging was performed in all 6 patients, with postcontrast T1-weighted imaging (T1WI) completed in all 6 patients and dynamic contrast-enhanced MR imaging, in 5. MR imaging findings of the tumor were evaluated with emphasis on the location, size, shape, margin, signal intensity, and pattern of enhancement.

RESULTS

The lesions appeared as solitary well-defined ovoid masses in the ciliochoroidal region in 5 patients and in the choroid in 1. With respect to the vitreous body, uveal schwannoma was hyperintense on T1WI spin-echo (SE) images in all 6 patients. The tumors were hypointense to the vitreous body on fast SE (FSE) T2-weighted images (T2WI) in 4 patients and isointense in 1. However, with respect to the brain, uveal schwannoma demonstrated isointensity on T1WI SE images in all 6 patients, isointensity on FSE T2WI images in 5 patients, and hyperintensity on T2WI SE images in 1. On postcontrast T1WI images, 3 patients showed markedly heterogeneous enhancement, and 3 showed markedly homogeneous enhancement.

CONCLUSIONS

Uveal schwannoma should be included in the differential diagnosis when an oval isointense mass relative to brain is seen in the ciliochoroidal region.

A pig-human comparative RH map comprising 20 genes on pig chromosome 13q41 that harbours the ETEC F4ac receptor locus

The enterotoxigenic Escherichia coli (ETEC) F4ac is a major cause of diarrhoea in newborn and young pigs. The locus for the intestinal ETEC F4ac receptor (F4acR) has been mapped to pig chromosome (SSC) 13q41 with known homology to human chromosome (HSA) 3q21 and q29. However, the causative gene and mutation(s) remain unknown. The aim of this study was to characterize gene-derived markers on SSC13q41 for fine mapping of the F4acR locus, and construct a high-resolution pig-human comparative map to select positional candidate genes for F4acR. Pig-specific sequence-tagged site markers were developed for 20 genes that are located in a 6.8-Mb region on HSA3q21 and q29, and a total of 34 single-nucleotide polymorphisms (SNPs) were identified in 14 of 20 markers developed. Eighteen markers were mapped to SSC13q41, while the other two markers (PLXNA1 and KLF15) were assigned to SSC13q32 and SSC7q13, respectively, by radiation hybrid mapping. This result showed that there was a small conserved segment on SSC7 corresponding to HSA3q21. A framework map comprising 18 markers on SSC13q41 was established, refining the synteny breakpoint on SSC13q41 to a region of 12.3 centiRay. The comparative radiation hybrid (RH) map revealed three interesting candidate genes for F4acR from the human genome, viz. MUC4, MUC13 and MUC20. Linkage analysis with six marker polymorphisms revealed that MUC4 had the most significant linkage with the F4acR locus.

High-level secretory production of recombinant human platelet-derived growth factor--BB by Saccharomyces cerevisiae under the non-selective conditions

Recombinant human platelet-derived growth factor-BB (rhPDGF-BB) was produced by Saccharomyces cerevisiae. A two-stage cultivation strategy with mixture of glucose and galactose was developed to enhance rhPDGF-BB production, with its concentration being 32 mg/l fermentation broth under optimal conditions: corn steep powder as nitrogen source, 2 g/1 of glucose concentration at the beginning of induction phase, a pH of 5.0 and 6.5 for cell growth and rhPDGF-BB accumulation. The purification process consisted of yeast supernatant ultrafiltration followed by ion exchange chromatography and molecular sieve, and the recovery of rhPDGF-BB was estimated to be 20.28%. Biological activity of the purified rhPDGF-BB was 3.05 ng/ml.